Re: Middle Track on the Myrtle

Under the BRT and the BMT the railroad directions were east-west. West was toward Park Row and later toward Broadway. An R train headed compass north on the 4th Avenue Line would be going "west." I think it's easy to see how much more sense that made.

After Unification it was changed to conform to IND and IRT practice, but I'm not sure exactly when.

Likewise, the SIRT was east-west, west was toward New Jersey, even if you were on a Tottenville train. I don't know what it is now.